Abstract: There is provided a method for producing a high-purity metal nitride by simple processes with good yield. Specifically provided is a method for producing a metal nitride including heating a metal hydride under a nitrogen gas or an ammonia gas.

Abstract: In accordance with the present invention, there is provided a calcium removal method capable of reducing operation cost. A solution L2 containing potassium or/and sodium, and calcium is passed through an ion-exchange resin 35 to separate the solution into a solution containing potassium or/and the sodium, and a solution containing calcium. Operation cost can remarkably be decreased since potassium carbonate is not required to remove calcium as before. Timing for changing a calcium-containing water L3 and a salt water L4 discharged from the ion-exchange resin can be performed based on at least one measurement result selected from the group consisting of: a calcium or chlorine concentration; electrical conductivity; and pH of a fluid which is discharged from said ion-exchange resin. The solution may be a filtrate L1 that is obtained by washing a chlorine bypass dust D generated in a cement burning process, or a leachate W of a final disposal site 50.

Abstract: To minimize harmful effects on operation due to scale adhesion while accommodating increase in the amount of generated chlorine bypass dust and suppress facility cost and running cost including medical agent cost low when incineration ash and dust contained in extracted cement kiln combustion gas are subject to water treatment. [Means for Solving Problems] A water treatment system 1 comprising: a dissolution tank 32 for dissolving a fly ash A in a water W; a dissolution tank 22 for dissolving a dust D contained in combustion gas extracted from a kiln exhaust gas passage running from an inlet end of a cement kiln to a bottom cyclone in a water W; and a vertical filter press 11 for separately filtering a slurry S2 fed from the dissolution tank 32 and a slurry S1 fed from the dissolution tank 22 from each other.

Abstract: To provide a device for removing radioactive cesium from waste material containing radioactive cesium, doing so at low energy and in a dependable manner. The removal device 1 for radioactive cesium is provided with: a rotary kiln 41 which is provided with a burner 41b supplying from the kiln outlet an organic matter O3 contaminated with radioactive cesium, and an inorganic matter charging port 41a supplying from the kiln inlet inorganic matter S4 contaminated with radioactive cesium, and which is employed to burn the organic matter O3 together with the inorganic matter S4; and a recovery device cooling tower 51, a cyclone 52, a bag filter 53 for recovering cesium that has volatilized in the rotary kiln. A drying/crushing device (dryer 21, crusher 22) for drying and crushing the organic matter O1 prior to charging the radioactive cesium-contaminated organic matter to the rotary kiln can be provided.

Abstract: In accordance with the present invention, there is provided an apparatus for fuelizing inflammable waste capable of efficiently fuelizing inflammable waste while reducing facility and operation costs of the overall system and maintaining stable operation, and so on. More particularly, the apparatus 1 for fuelizing inflammable waste comprises: a primary crusher 4 for crushing an inflammable waste W containing as principal component at least one selected from a group comprising plastics, sponges, fibers, rubbers and wood materials; a foreign matter removing device 7 for removing foreign matters F contained in the crushed objects W1; a secondary crusher 9 for secondarily crushing the crushed objects W3 from which foreign matters I, M are removed; and an injecting device 11 for injecting the secondarily crushed objects W4 generated by the secondary crusher 9 into a burner 10, and so on.

Abstract: Provided is a combustion gas bleeding probe, which is elongated in lifetime and improved in chlorine removing ability and so on. The combustion gas bleeding probe (1) comprises a cold gas discharge means having a plurality of discharge ports (2b) for discharging cold gases (C) substantially perpendicularly of the suction direction (S) of a combustion gas (G) and toward the center of the combustion gas flow. A vector (A), which is composed of momentum vectors (MVs) of the cold gas (C) discharged individually from the plural discharge ports, has a vertically downward component. This vertically downward component of the synthesized vector is made the larger, as the angle between the suction direction of the combustion gas and the flow direction of the combustion gas before sucked by the probe becomes the closer to a right angle.

Abstract: An apparatus and a method for removing unburned carbon from fly ash capable of suppressing facility cost and stably conducting performance adjustment depending on property of the fly ash. The method comprises the steps of: adding water to fly ash to produce slurry; adding collector to the slurry, feeding the slurry and the collector to a static-type mixer 4, a venturi pipe 24 or the like to add shearing force to them; adding frother to them to generate air bubbles; and adhering unburned carbon of the fly ash to the air bubbles to raise the unburned carbon. The frother and air can be fed to the static-type mixer or the like together with the slurry and the collector. Depending on the change in property of the fly ash, the number of the static-type mixers or the like used in series can be increased or decreased, and depending on required capacity, the number of the static-type mixers or the like used in parallel may be increased or decreased.

Abstract: To provide a method and an apparatus for removing radioactive cesium from waste containing radioactive cesium at low cost. A radioactive cesium removal apparatus 1 including: an incinerator 22 for burning an inflammable waste polluted with radioactive cesium; a suspension preheater 23 for, with the combustion exhaust gas G5 and a sensible heat of the incineration ash of a combustible C discharged from the incinerator, generating calcium oxide or/and magnesium oxide from a source of calcium oxide or/and a source of magnesium oxide, cyclones of the suspension preheater being arranged in multistages; a rotary kiln 21 for burning an inorganic substance S polluted with radioactive cesium together with the calcium oxide or/and the magnesium oxide and the incineration ash D3 including the radioactive cesium; and collectors 31, 32 for collecting cesium volatilized in the rotary kiln.

Abstract: A high-purity silicon carbide powder and its production method enable mass production of the high-purity silicon carbide powder at low cost in a safe manner. The content of impurities in the silicon carbide powder is 500 ppm or less. The silicon carbide powder can be obtained by heating a raw material for silicon carbide production in an Acheson furnace using a heat generator. The raw material for silicon carbide production is prepared by mixing a siliceous raw material and a carbonaceous raw material. The raw material for silicon carbide production contains the siliceous raw material and the carbonaceous raw material at a mixture mole ratio (C/SiO2) of 2.5 to 4.0 and has a content of impurities of 120 ppm or less.

Abstract: To provide a low price industrial salt by reducing facility and operation costs without electro-deposition and crystallization and through reduction in quantity of chemicals used. An industrial salt S obtained by the steps of: extracting a part of combustion gas from a kiln exhaust gas passage running from an inlet end 12b of a cement kiln 12 to a bottom cyclone 13; recovering dust D from the extracted gas G2 and washing recovered dust; and drying a filtrate L1 after the washing in a gas stream. The industrial salt can be obtained by removing a calcium component from the filtrate and drying the filtrate from which the calcium component is removed in a gas stream. Further, from the filtrate can be removed sulfate radical, and drying the filtrate from which the calcium component is removed in a gas stream to obtain the industrial salt. For the drying can be used an exhaust gas discharged from a clinker cooler 12a and a spray drier 43 may be used for the drying.

Abstract: A particle formed of silica and carbon having a low impurity content and an excellent reactivity is provided. Also provided is a method of producing a silica and carbon-containing material including: (B) a carbon mixing step of mixing an aqueous alkali silicate solution having a silicon concentration within the liquid portion of at least 10 wt % with carbon so as to obtain a carbon-containing aqueous alkali silicate solution; and (C) a silica recovery step of mixing the carbon-containing aqueous alkali silicate solution with a mineral acid so as to cause carbon and silicon within the liquid portion to precipitate as particles formed of silica and carbon and thus obtaining a particle-containing liquid substance, then solid-liquid separating the liquid substance so as to obtain a solid portion of a silica and carbon-containing material which is an assembly of particles formed of silica and carbon and a liquid portion containing impurities.

Abstract: A combustion exhaust gas processing device comprises: a dust collector collecting dust in a cement kiln combustion exhaust gas; a wet dust collector using sodium hypochlorite as a catalyst-poisoning-substance stripper for removing a catalyst-poisoning substance and mercury from a combustion exhaust gas which passed the dust collector; heaters downstream of the wet dust collector for heating the combustion exhaust gas from the wet dust collector; and a catalyst device from which NOx, a persistent organic pollutant, etc. in the heated combustion exhaust gas, are removed. An upstream side of the catalyst device is installed with an oxide catalyst such as titanium-vanadium and a downstream side is installed with a platinum catalyst as a noble-metal catalyst. The temperature of the combustion exhaust gas after the wet dust collector is increased up to 140° C. or more with the heaters to prevent decline in denitration efficiency of and the decomposition efficiency of a volatile organic compound.

Abstract: An object of the present invention is to provide a heavy metal removing apparatus which can efficiently remove the heavy metal contained in the dust produced by burning of the raw material containing the heavy metal, and a cement production system comprising the heavy metal removing apparatus. The heavy metal removing apparatus 10 comprises a cyclone separator 11 which separates exhaust gas containing the heavy metal from a part of the dust heated to a temperature equal to or more than a temperature at which the heavy metal can volatilize, a bag filter 13 which is connected to the subsequent stage of the cyclone separator 11 and separates the exhaust gas containing the heavy metal from the remainder of the dust, and a heavy metal removal tower 14 which is connected to the subsequent stage of the bag filter and removes the heavy metal from the exhaust gas.

Abstract: A cement manufacturing apparatus capable of increasing quantity of fly ash used in the apparatus while controlling unburned carbon content in cement within a permissible range. The cement manufacturing apparatus comprises a removal means for removing unburned carbon from gypsum, and a grinding means for grinding gypsum from which unburned carbon is removed by the removal means together with clinker to generate cement. With the apparatus, total unburned carbon content in cement can be reduced, and the quantity of fly ash used in the apparatus can be, increased by the reduced amount of unburned carbon. The removal means can remove unburned carbon contained in gypsum as well as unburned carbon contained in fly ash, and the grinding means may grind the fly ash from which unburned carbon is removed together with the gypsum, from which unburned carbon is removed, and clinker.

Abstract: In accordance with the present invention, there is provide and device and method to facilitate the treatment of chlorine bypass dust while preventing increases in chemical cost and concentrations of heavy metals in clinker, and ensuring stability in quality of cement, and to treat chlorine bypass exhaust gas while avoiding coating troubles in a cement kiln etc., and preventing heat losses in a preheater etc., without degradation of clinker production amount.

Abstract: Provided is a piezoelectric element including: an electrode portion including a piezoelectric layer and an electrode layer that are laminated; and a non-electrode portion that is in contact with the electrode portion and includes a piezoelectric layer without an electrode layer, in which the non-electrode portion includes a region having a density smaller than a density of the piezoelectric layer of the electrode portion.

Abstract: Provided is cement burning apparatus 1 comprising a dryer 6 for drying high-water-content organic waste of which water content is 40 mass percent or more, in which combustion gas extracted from outlet portions or ceiling, portions of preheater cyclones 3A to 3D of a cement kiln 2 is fed to the dryer 6. As the dryer 6, a grinding-type flash dryer, which directly contacts the combustion gas G with the high-water-content organic waste W while grinding it, can be used. In addition, the apparatus 1 further comprises a coarse powder separator 12 for separating coarse powder from the combustion gas extracted from the range described above, and the combustion gas G from which dust is separated by the coarse powder separator 12 can be fed to the dryer 6, and the dust concentration of the gas fed to the dryer 6 may be adjusted to 0.05kg/Nm3 or more and 0.35kg/Nm3 or less.

Abstract: Unburned carbon is efficiently removed from fly ash, and effective utilization of the fly ash and removed unburned carbon is attained. Water is added to fly ash to thereby obtain a slurry. A collector is added to the slurry, and shearing force is applied to the slurry and collector to thereby attain a surface modification. The mixture is subjected to flotation operation at which unburned carbon of fly ash is attached to froths and surfaced. The application of shearing force to the slurry and collector can be carried out by means of a submerged agitator whereby an agitation power of 0.7 to 10 kWh/m3 is applied per unit quantity of slurry. The fly ash concentration of the slurry is in the range of 3 to 50 wt. %, and the amount of collector added is in the range of 5 to 100 wt. % based on the amount of unburned carbon of fly ash. The unburned carbon separated by flotation can be used as fuel, and the fly ash (product) having its unburned carbon content reduced to 1 wt.

Abstract: A combustion exhaust gas processing device comprises: a dust collector collecting dust in a cement kiln combustion exhaust gas; a wet dust collector as a catalyst-poisoning-substance stripper removing a catalyst-poisoning substance from a combustion exhaust gas which passed the dust collector, preheaters heating beforehand a combustion exhaust gas which passed the wet dust collector; and a catalyst device from which NOx, a persistent organic pollutant, etc. in the preheated combustion exhaust gas, are removed. A titanium-vanadium catalyst etc. as an oxide catalyst is used upstream of the catalyst device, and a platinum catalyst etc. as a noble-metal catalyst downstream of the catalyst device. The temperature of the combustion exhaust gas after the catalyst-poisoning substance is removed is increased up to 140° C. or more with the preheaters to prevent decline in denitration efficiency of and the decomposition efficiency of a volatile organic compound.

Abstract: In accordance with the present invention, there is provide and device and method to facilitate the treatment of chlorine bypass dust while preventing increases in chemical cost and concentrations of heavy metals in clinker, and ensuring stability in quality of cement, and to treat chlorine bypass exhaust gas while avoiding coating troubles in a cement kiln etc., and preventing heat losses in a preheater etc., without degradation of clinker production amount.